Grub not showing up boots directly into Windows 10

I’m not very (or not at all) experienced with Ubuntu and I’ve been trying to fix this problem, I’d very much appreciate your help.

I have an HP Pavilion Notebook with Windows 10 pre-installed. After installing Ubuntu in dual-boot, the Laptop rebooted showing me the GRUB, but it only happened once and now it boots directly into Windows 10. One thing I don’t know if it’s relevant to mention is that the first and only time the GRUB appeared the Windows option said “Windows boot manager” instead of the “Windows 10 (loader)” that appears on my Desktop (which also has dual-boot).

I have done two things from what the best answer on this post suggested
(Grub not showing on startup for Windows 8.1 Ubuntu 13.10 Dual boot).

Which are:

  1. Disable Fast Boot on Windows 10.
  2. Run bcdedit /set {bootmgr} path EFIubuntugrubx64.efi on Windows 10.

After that the following can be read

If you’re booting with Secure Boot active, change grubx64.efi to shim.efi (or maybe it’s shimx64.efi; in Linux, check the contents of /boot/efi/EFI/ubuntu to see what’s there)

Since I have Secure Boot Active (and mildly reluctant to turn it off since I read that some users had some problems with booting to any OS when done so), I went to check /boot/efi… in the live session, but I found nothing there. /boot/efi is empty or maybe its contents can’t be visualized.

Also, I have noticed that in the BIOS menu there’s no Ubuntu or Grub Option, just the standard OS, USB,etc. I do have that option in my Desktop’s BIOS.

What to do from here?